Digital information recording apparatus, reproducing apparatus and transmitting apparatus

ABSTRACT

A digital information recording apparatus includes a recording circuit for recording information of a retention period included in the digital information and indicating a period for permitting the digital information to be held in the recording medium, starting with a time at which the digital information is recorded on the recording medium; and information of a playback permission period included in the digital information and indicating a period for permitting the digital information to be played back starting with a time at which the information is reproduced initially following recording of the digital information on the recording medium, permitting temporary recording or copying for the information permitted for “copy never” or “copy one generation.”

CROSS REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. application Ser. No.14/713,515, filed May 15, 2015, which is a Continuation of U.S.application Ser. No. 13/649,882, filed Oct. 11, 2012, now U.S. Pat. No.9,083,942, issued Jul. 14, 2015, which is a Continuation of U.S.application Ser. No. 11/834,340, filed Aug. 6, 2007, now U.S. Pat. No.8,311,389, issued Nov. 13, 2012, which is a Continuation of U.S.application Ser. No. 09/982,291, filed Oct. 19, 2001, which claimspriority from Japanese patent applications JP 2001-002053, filed Jan.10, 2001, JP 2000-384891, filed on Dec. 13, 2001 and JP 2000-393271,filed Dec. 21, 2000, the contents of which are incorporated byreferences.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an apparatus for recording orreproducing digital information such as video and audio data, moreparticularly, to digital information recording and reproducing apparatuscapable of setting a limit to playback or copying of the information tobe recorded or reproduced by the authority of copyright holders and thelike. Further, the present invention relates to a transmitting apparatussuitable for transmitting digital information to the recording andreproducing apparatus as above.

Description of the Related Art

Digital television broadcasting has been started and digital recordingand reproducing apparatus for recording and reproducing digitalinformation have been brought to market. In addition, even in the fieldof package medium such as movie software, package software to be usedwith this type of apparatus will be developed and practiced in the nearfuture.

The digital recording scheme has an advantage that the quality is notdeteriorated or very less degraded in the recording and reproducingprocess. But in the event that many high-quality copies are prepared andcirculated at a site unknown to a copyright holder, there arises aproblem that profits cannot be returned to the copyrighters. This is apending problem for which countermeasures have been discussed in variousfields since a case of digital audio tape deck at issue.

For example, JP-A-11-146378 discloses a method of preventing preparationof high-quality copies by degrading the quality in advance of digitallyrecording information.

U.S. Pat. No. 5,896,454 discloses a method of adding copy controlinformation of 2 bits to data information. In the method, any one ofcopy inhibition, copy approval and copy approval for only one generationis selected of volition of copyright holders or information planners tocontrol the operation of a recording apparatus. The recording apparatusdoes not perform recording operation if copy inhibition is selected butperforms recording operation if copy approval is selected. With copyapproval for only one generation selected, the recording apparatusrewrites this control information into information for inhibiting anymore copies and then operates to record.

In other words, the copy control information useful for the informationdata planner to control copying operation by users has been proposed.For example, codes of “copy never” (copy inhibition), “copy onegeneration” (for permitting only one copy), “no more copies” (data oncecopied through “copy one generation” is not permitted for more copies)and “copy free” (approval of copying) are set in a header part of dataor a watermark (WM), very difficult to detect, is embedded in an image.The above expedient is expected to solve the problem without inflictinga one-sided loss on the copyright holders or users.

But, even in case the stringent inhibition, for example, “copy never” isimposed, there is obviously a spontaneous need for temporarily recordinginformation on, for example, a hard disc of a receiving apparatus andplaying back the information and therefore, with a view of mitigating aloss on the side of users, a means for this purpose is necessary. Atthat time, it must also be considered to mitigate a loss on the side ofcopyright holders.

More particularly, when a visitor comes accidentally while the copycontrol information being set to “copy never” in broadcasting, a user inquestion disadvantageously looses a chance of playing back a broadcastprogram. Under the circumstances, JP-A-2000-149417 discloses a method ofeliminating such a problem by using a means “temporary recording” evenwhen the copy control information designates “copy never”. According tothe method, information is once recorded physically on a recordingmedium and a limit of 90 minutes for instance is set to the period forreproduction and playback and the information is erased after a playbackor at the termination of the period. In other words, the recording isnot for long-term conservation and multipurpose utilization but simplypermits the broadcasting to be equivalently played back 90 minuteslater. Since the information on the recording medium does not remain fora long time, the aforementioned inconvenience of users can be eliminatedwithout inflicting an unprofitableness to the copyright holders. Thetemporary recording is, because of its nature, carried out frequently byusing a hard disc recorder built in the receiving apparatus.

SUMMARY OF THE INVENTION

Various kinds of expedience disclosed in the above documents give asolution to the problems. But the problem involved in copyright cannotbe solved satisfactorily by the conventional methods that inflictone-sided profit or loss to copyright holders, broadcasting or softwaredeveloping firms or general users.

Further, the “copy one generation” conveniently gives the users a chanceof backing up the information recorded temporarily on a hard disc forinstance. As a rule, once the temporarily recorded information iscopied, the copy control information changes to “no more copies” toprevent any more copying. But, when copying of the temporarily recordedinformation is permitted, though only once, the copy permission remainsfor a long time, giving anxiety to the copyright holders. On the otherhand, when “no more copies” is once set, desired exchange of the mediumstoring the contents becomes impossible and disadvantageously the usersare forced to suffer from inconvenience.

In the light of the above problems, an object of the present inventionis to provide more specifically a unit for preventing circulation ofunauthorized copies and permitting the user to perform conditionalplayback and the like.

Another object of the invention is to provide a unit for eliminating theaforementioned anxiety of the copyright holders and inconvenience of theusers through a method of meeting the compatibility between profits ofthe user and the copyright holder.

Still another object of the invention is to provide a unit for limitinga condition for permitting playback of recorded information for instanceso as to enable the copyright holder to further control the range ofinformation utilization.

According to the invention, the effective period, available inside arecording medium, of information permitted for temporary recording isprescribed. The apparatus has a unit for disabling reproduction andplayback after expiration of a prescribed time following recordinginitiation. Through this, the information temporarily recorded on themedium can be prevented from being used later for unauthorized purposes.The effective period inside the recording medium referred to herein willbe called “retention period”. Further, the effective period startingwith playback initiation is also prescribed. The apparatus has a unitfor disabling repetitive reproduction and playback after expiration of aprescribed time following the initial start of playback. Through this,playback by many and unspecified users can be prevented. The effectiveperiod referred to herein will be called “playback permission period”.Frequently, the retention period is set to be equal to or longer thanthe playback permission period but this is not limitative. Many types ofreproducing apparatus cause their operation to temporarily pause or stopduring reproduction. Accordingly, even when reproduction is startedduring the playback permission period, the retention period sometimeshappens to stop or end before the playback comes to an end. In thatcase, concurrently with the stop of the retention period, reproductionis disabled to proceed any more. Alternatively, for convenience ofusers, even with the retention period stopped, a part of informationsucceeding the stopping location is once allowed for continuous playbackup to the end. In that case, conditionally, further pause and stop areinhibited.

In some case, a part once subjected to playback is inhibited forrepetitive playback. This can be implemented by disabling backward feedof the medium or making, in some way, a part once subjected to playbacknon-reproducible during backward feed.

When the copyright holder originally sets a limit to copying such as“copy one generation” for instance, copying permitted for the user islimited to some extent. To prevent the temporarily recorded informationfrom staying in the medium for a long time while being conditioned to“copy one generation”, the present invention prescribes the effectiveperiod for the information, conditioned to “copy one generation” to stayin the recording medium following, recording of the information. Theapparatus has a unit for handling the information as being subject to“no more copies” after expiration of the prescribed period followingrecording so as to prevent copying, thereby eliminating anxiety of thecopyright holder about the long-term stay of the information subject to“copy one generation”. The effective period referred to herein will becalled “copy permission period”. In the medium in which the copypermission period has expired or information is copied within the copypermission period, the copy control information changes to “no morecopies” to disable copying.

In that case, by permitting “move” operation for moving the informationto another medium on the presupposition that the original information isto be erased, inconvenience of the user can be obviated. As necessary,the period for permitting the move mode after the control informationhas changed to “no more copies” or the period for permitting repetitivemove after the preceding move may be prescribed. The effective periodreferred to herein will be called “move permission period”.

When the operation is caused to temporarily pause or stop duringreproduction even if copying is started during the copy permissionperiod, the move permission period will sometimes be stopped before itcomes to an end. In that case, concurrently with the stoppage of thecopy permission period, any more copying is inhibited. Alternatively,for convenience of the user, even with the copy permission periodstopped, a part succeeding the stop location can once be allowed forcontinuous copying up to the end. In that case, conditionally, furtherpause and stop are inhibited.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the presentinvention will become more readily apparent from the following detaileddescription when taken in conjunction with the accompanying drawingswherein:

FIG. 1 is a block diagram showing an embodiment of the configuration ofthe whole of a digital information transmitting, receiving, recordingand reproducing system to which digital information recording apparatus,reproducing apparatus and transmitting apparatus according to theinvention are applied;

FIG. 2 is a block diagram showing an embodiment of the digitalinformation transmitting apparatus according to the invention;

FIG. 3 is a block diagram of a digital information receiving side inFIG. 1;

FIG. 4 is a block diagram showing an embodiment of a recording circuitin the digital information recording apparatus according to theinvention;

FIG. 5 is a block diagram showing an embodiment of a recording andreproducing unit in the digital information recording apparatus andreproducing apparatus according to the invention;

FIG. 6 is a block diagram showing an embodiment of a reproducing circuitin the digital information reproducing apparatus according to theinvention;

FIG. 7 is a block diagram showing another embodiment of the reproducingcircuit in the digital information reproducing apparatus according tothe invention;

FIG. 8 is a diagram showing an embodiment of the structure of firstcontrol information according to the invention;

FIG. 9 is a diagram showing an embodiment of the structure of copycontrol information according to the invention;

FIG. 10 is a diagram showing an embodiment of the structure of secondcontrol information according to the invention;

FIG. 11 is a diagram showing an embodiment of recording data onrecording medium according to the invention;

FIG. 12 is a block diagram showing still another embodiment of thereproducing circuit in the digital information reproducing apparatusaccording to the invention;

FIG. 13 is a block diagram showing another embodiment of the recordingcircuit in the digital information recording apparatus according to theinvention;

FIG. 14 is a block diagram showing another embodiment of the digitalinformation reproducing apparatus according to the invention; and

FIG. 15 is a block diagram showing an embodiment of an erasing circuitin the digital information reproducing apparatus according to theinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a block diagram showing an overall configuration of atransmitting, receiving, recording and reproducing system including aninformation distributor. The present invention involves a recordingapparatus, a reproducing apparatus and a transmitting apparatus, havinga reproducing circuit 1, a recording circuit 2, an informationdistributor 3 such as a broadcasting station, a repeater 4, a tuner forRF (radio frequency) 5, a recording/reproducing unit 6 and a display 7.

The information distributor 3 such as a broadcasting station transmits asignal electromagnetic wave modulated with information through themedium of the repeater 4 such as, for example, a broadcasting satellite.Otherwise, transmission based on a cable may be employed. The RF tuner 5on the receiving side receives and demodulates the transmittedinformation and thereafter, the recording circuit 2 converts it into asignal suitable for recording on a recording medium and therecording/reproducing unit 6 records the converted signal. Therecording/reproducing unit 6 also reproduces the information from therecording medium. A reproduction signal is applied to the display 7through the reproducing circuit 1 to ensure playback of the informationrepresenting original video and audio data. Though not illustrated, thereceived information can also be played back directly. In caseinformation recorded in advance on a removable recording medium isserviced, only the operation succeeding the reproducing operation by therecording/reproducing unit 6 is carried out.

FIG. 2 is a block diagram showing an embodiment of the construction ofthe information distributor 3 (transmitting apparatus) such as abroadcasting station. The transmitting apparatus comprises a programgenerator 31, an encode circuit 32 for performing compression based on,for example, MPEG scheme, a scrambler circuit 33, a modulator circuit34, a transmitting antenna 35, a service information applying circuit 36and an input terminal 37.

The amount of data in information such as video/audio informationgenerated by the program generator 31 constituted of a camera orrecording/reproducing device is compressed by the encode circuit 32 sothat the information may be transmitted with a less bandwidth. Asnecessary, the information is encrypted by means of the scramblercircuit 33 to enable a specified audience to take part in playback. Theencrypted information is modulated to a signal suitable for transmissionby means of the modulator circuit 34 and then is emitted from thetransmitting antenna 35 in the form of an electric wave directed to therepeater such as, for example, a broadcasting satellite. In this phase,the service information applying circuit 36 adds information such ascopy control information and retention information and playback/copypermission period information. In addition to the above information, thepresent time information may be applied which can be utilized as a startpoint of the retention period and copy permission period. For example,request information is inputted to the input terminal 37 through atelephone line for instance. This is utilized for the case where theinformation to be transmitted is determined in response to a requestfrom audiences as exemplified by video-on-demand.

FIG. 3 is a block diagram showing an embodiment of the RF tuner 5 shownin FIG. 1. The RF tuner 5 includes an RF/IF converter circuit 51, ademodulator circuit 52, a descrambler circuit 53 for decoding ordecrypting the cipher applied to the signal and an output terminal 54.

An electric field from the repeater, for example, a broadcastingsatellite is inputted to the RF/IF converter circuit 51. The RF-bandelectric wave is converted in frequency to a frequency of IF(intermediate frequency) band or is converted into a signal of aconstant band independent of a receiving channel. The demodulatorcircuit 52 releases the modulation operation applied for the purpose oftransmission. The cipher in the demodulated signal is then decrypted bythe descrambler circuit 53 and then delivered to the output terminal 54.

FIG. 4 is a block diagram showing an embodiment of the recording circuit2. The recording circuit 2 has an input terminal 201 for a signal to berecorded, a memory circuit 202 such as a semiconductor memory, arecording signal processing circuit 203, an output terminal 204 for asignal to be recorded on a recording medium, an information detectioncircuit 205, a recording control circuit 206, a clock 107 and an inputterminal 208 for records of a control signal during reproduction.

The signal inputted through the input terminal 201 is applied withvarious control codes. As an example, a signal applied with the copyinformation “copy never” and designated with the aforementionedretention period and playback permission period will be described. Inthe case of broadcasting, the data as above is applied to theinformation by means of, for example, the service information applyingcircuit 36 of FIG. 2. The inputted data is once stored block by block inthe memory circuit 202. Then, the data is fed to the informationdetection circuit 205 which in turn detects the control informationconcerning copying. Subsequently, the recording control circuit 206decides on the basis of the data as above whether the signal ispermitted for recording and sends a decision result to the recordingsignal processing circuit 203. The recording signal processing circuit203 has already been applied with the data from the memory circuit 202and on the basis of the control signal from the recording controlcircuit 206, it interrupts the signal when recording is inhibited butapplies a modulation suitable for the medium used when recording ispermitted, thus delivering a modulated signal to the output terminal204. The output signal is recorded on a medium such as a tape or disc.For example, even when the control information is “copy never”, theoutput signal is recorded temporarily on the medium if the effectiveretention period and playback permission period are designated.Obviously, instead of being detected by the information detectioncircuit 205, the control signal may be applied externally, separatelyfrom video/audio data.

When recording is permissible, the information including the copycontrol information and the retention period and playback permissionperiod is generated by the recording control circuit 206 and is added tothe recording signal by means of the recording signal processing circuit203. As necessary, the present time during recording delivered out ofthe clock 107 is also recorded concurrently. If the present time isincluded in the received information, this data may be used or the clock107 may be set by the received information. Through this, the presenttime during recording can be prevented from being altered.

With the aforementioned control information being “copy any generation”,if the effective copy permission period is designated or the movepermission period is designated as necessary, information is recordedtemporarily on the medium while keeping “copy one generation” unchanged.In case the control information is “no more copies”, copying isinhibited as a rule and therefore, the output of, for example, therecording signal processing circuit 203 is interrupted. In the case ofan apparatus in which the aforementioned move mode is permitted,however, recording of information onto the medium is permitted even for“no more copies” on the premise that a counterpart of the information onthe side of the apparatus transmitting that information will be erased.In that case, it is sometimes necessary to transmit, to the apparatus onthe recording side, information as to whether the erase operation of thetransmitting apparatus is adapted to the move mode. Instead of detectingthe control information inclusive of such information as just mentionedabove by means of the information detection circuit 205, thatinformation may be applied externally separately from the video andaudio data.

If the aforementioned move permission period is additionally designated,even the apparatus adapted to the move mode is not permitted to do movewhen the above move permission period runs out or expires.

Even with the detected control information being “copy one generation”,in the absence of information such as copy permission period, thecontrol information is changed to “no more copies” by means of therecording signal processing circuit 203 during recording.

FIG. 5 is a block diagram showing an embodiment of therecording/reproducing unit 6 shown in FIG. 1. The recording/reproducingunit 6 includes an input terminal 61, a recording amplifier 62, arecording media drive 63 carrying a recording medium such as a harddisc/digital video disc/video tape, a reproducing amplifier 64, anoutput terminal 65, a mechanism control circuit 66 and an input terminal67.

The output signal of the recording circuit 2 is supplied to the inputterminal 61. This signal is amplified by the recording amplifier 62 soas to be able to drive a laser generation device or a magnetic head andis then recorded on the recording medium as above by means of therecording media drive 63. A signal reproduced from the recording mediumis amplified by the reproducing amplifier 64 up to a level that canafford to be processed in the succeeding stage of signal processing andthereafter delivered to the output terminal 65. The mechanism controlcircuit 66 is for a motor used to drive the recording media drive 63 andis responsive to a control signal inputted to the input terminal 67 tocontrol the recording medium. Though not illustrated, the control signalinputted to the input terminal 67 is fed from the recording circuit 2 orreproducing circuit 1.

FIG. 6 is a block diagram showing an embodiment of the recording circuit1 of the information reproducing apparatus according to the invention.The reproducing circuit 1 includes an input terminal 101 for areproduction signal, a reproducing signal processing circuit 102, ablock detection circuit 103, a memory circuit 104 such as asemiconductor memory, an error correction circuit 105, a signal outputcircuit 106, a clock 107, a decoder 108 for decoding moving picturecompression, a watermark detection circuit 109 for decryption of awatermark embedded in an image, an output terminal 110 for sending asignal to the display, an information detection circuit 111 for controlsignals, an output control circuit 112 for deciding, on the basis of acontrol signal, whether delivery of a reproduction signal ispermissible, an output terminal 113 for the signal kept away fromdecoding of the cipher, an output terminal 114 for a decision result,and an output terminal 116 for the control information delivered to theinput terminal 208 of recording circuit 2.

The following description will be given by way of a case in which dataconcerning the aforementioned retention period and playback permissionperiod are included in the reproduction signal supplied to the inputterminal 101. The signal is fed to the reproducing signal processingcircuit 102. In this circuit, the modulation applied on the recordingside for the purpose of performing recording/reproduction on/from themedium is demodulated, the waveform equalization is carried out and datais settled by a clock. Subsequently, in the block detection circuit 103,synchronization and ID signals are detected, on the basis of thesesignals, reproduction data is once stored at a predetermined location inthe memory circuit 104. The error correction circuit 105 detects fromthe stored data a code error generated in the course of recording andreproduction through arithmetic operation to provide a corrected value.Data subject to error correction is sent to the decoder 108 through thesignal output circuit 106.

An output of the signal output circuit 106 is also supplied to theoutput terminal 113 so as to be used for further copying by a differentrecording device connected to this terminal 113. But in the case of asignal applied with stringent copy limit as described previously, thesignal delivered from this output terminal is subject to “copy never”and therefore, copying often fails to fulfill itself. An output ofoutput control circuit 112 to be described later may be supplied to thesignal output circuit 106 to prevent the signal from being delivered tothe output terminal 113.

On the other hand, from the data applied with the previous errorcorrection, the information detection circuit 111 for control signaldetects data indicative of the retention period and playback permissionperiod. One data detection operation per one frame of an image sufficesto provide sufficient information as will be described later and thedata may be set to the header of a recording track in the case of, forexample, a tape medium. Alternatively, the data detection operation asabove may be once performed at intervals of a predetermined amount ofdata. If that data is recorded frequently, thinning-out detectionoperation may be carried out during reproduction. Then, the outputcontrol circuit 112 decides, on the basis of the detected retentionperiod and playback permission period as well as playback start time,time for recording and the present time from the clock 107, whether thedelivery of reproduction output is permissible, thereby controlling theoutput to the decoder 108. The information detection circuit 111 mayalso detect the control signal for “copy never” and “no more copies” inorder for the output of the output control circuit 112 to control thesignal output circuit 106, thus ensuring that when copying is inhibited,the delivery of the reproduction signal to the output terminal 113 canbe prevented.

The output of the output control circuit 112 is also applied to theoutput terminal 114. This output signal is used when the signal detectedby the information detection circuit 111 includes information forconditionally permitting a device connected externally to carry outrecording/reproduction, in order to transmit the information to theoutside. When it is determined that the retention period has alreadyexpired, information indicative of this expiration may be supplied fromthe output terminal 114 to the aforementioned input terminal 67 of FIG.5 to stop the recording media drive 63.

The moving image data compression applied in advance of the transmissionby the decoder 108 is decoded from the output of the signal outputcircuit 106 and a resulting signal is fed to the output terminal 110 topermit playback with the display connected to the output terminal 110.As the output from the output terminal 110, an intact decoded digitalsignal may be delivered or an analog signal converted from the digitalsignal may be delivered.

When a copyright holder, copy control information and the like areembedded as a watermark in an image, the watermark detection circuit 109operates to detect the watermark. In place of the signal detected by theinformation detection circuit 111, the information detected from thewatermark may be used to perform a similar control operation.

The clock 107 is of course required of accuracy to some extent. If theclock can easily be altered with malicious intent of the user, then itwill not fulfil itself. Further, it is desirable that the clock becontrollable in response to time information from, for example, thebroadcasting station. The clock may be designed to make the apparatusinoperative when the time is altered intentionally.

Next, in connection with the case in which the reproduction signalapplied to the input terminal 101 includes data concerning theaforementioned copy permission period, only operation differing fromthat described as above will be described. In this case, the informationdetection circuit 111 for control signal detects data of the copycontrol information, for example, “copy one generation” and the copypermission period. The output control circuit 112 decides, on the basisof the detected control information and copy permission period as wellas recording time and the present time from the clock 107, whethercopying is permissible and sends a decision result to the signal outputcircuit 106. If the copy information “copy one generation” is availablewithin the copy permission period, the signal output circuit 106 passesthe reproduction signal. On the medium of the external device forpreparation of copies, the control signal is changed to “no morecopies”. If the copy information “copy one generation” is outside thecopy permission period, the control information can be rewritten to “nomore copies” to disable the external device to copy. As necessary, theinformation in the medium may be rewritten to “no more copies” by meansof the recording circuit. Obviously, rewrite on the reproducing side bythe signal output circuit 106 is not limitative and it may be done withanother reproducing circuit block.

FIG. 7 is a block diagram showing another embodiment of the reproducingcircuit according to the invention. Constituent components identical tothose in the FIG. 6 embodiment are designated by identical referencenumerals. The present embodiment differs from the FIG. 6 embodiment inthat the decoder 108, watermark detection circuit 109 and outputterminal 110 are removed. These components are often built in thedisplay 7 of FIG. 1 and in that case, the reproducing circuit isseparated as a unitary circuit, leading to the construction shown inFIG. 7. On the basis of the information, such as retention period,playback permission period, copy permission period and copy controlinformation, detected by the information detection circuit 111, theoutput control circuit 112 sends a control signal to the signal outputcircuit 106 in order to control permission/inhibition of the delivery ofthe signal to the outside and rewrite of the control information. Thesignal at the output terminal 113 can be supplied to the display as wellas another external recording device as in the case of the FIG. 6embodiment.

FIG. 8 is a diagram showing an embodiment of a first control signaltransmitted from the information distributor 3 and recorded on therecording medium during recording in the foregoing embodiments. In thecase of a tape medium for instance, recording of one first controlsignal on one recording track suffices but obviously, the first controlsignal is recorded in a predetermined relationship with video and audiodata to assure easy separation of the first control signal duringreproduction. Program number 300 indicates what number is allotted to aprogram in question on the medium. Sector information 301 indicatesnumbers allotted to sectors set up by dividing the program in apredetermined unit. The division can be made in a fixed unit, forexample, in a unit of 2 k bytes or in a constant unit of information,for example, in a unit of division during encoding. The numbers may beset up within the program or may be serial numbers set up throughout therecording medium.

Information such as recording time 305 to be described later is added ina unit of sector. Time information 302 indicates how long the recordingpart of interest proceeds after start of the program. Type information303 indicates attribute information of the program as to whether theprogram is sold, rental, self-made or distributed from broadcasting.Copy control information 304 indicates the aforementioned controlinformation such as “copy never”, “copy one generation” or the like.

FIG. 9 shows a structure of the copy control information 304. Versionnumber 311 indicates which version the information belongs to. As willbe described later, the copy control information 304 must be so flexibleas to add some items other than those shown in FIG. 9 or to erase someitems from FIG. 9, as necessary. Accordingly, with a view of determininghow what information is arranged in sequence in various ways, theversion is managed. For example, when 8 bits are allotted to the versioninformation 311, the copy control information 304 can be used in 256ways.

Output control 312 controls the permission/inhibition of delivery of theoutput from the digital output terminal 113 or the analog outputterminal 110. For control of the output delivery, it is first decided,from the form of the output and encryption conditions, whether safetycan be assured and then the permission/inhibition of the output deliveryis controlled. Further, the output delivery permission/inhibition may becontrolled depending on resolution for instance. For example, in thecase of a video signal of high resolution such as high vision video,control is such that the video signal as it is may be inhibited frombeing delivered but a video signal set up by degrading the resolutionmay be permitted for delivery.

Copy control information 313 (CGNS; Copy Generation Management System)controls copying to a digital recording device. For example, when thisinformation is of 2 bits, “11” may designate “copy never”, “10” maydesignate “copy one generation”, “01” may designate “no more copies” tothe effect that one copy obtained through “copy one generation” is nomore permitted for copying, and “00” may designate “copy free”.Different CGMS's may be provided for the digital signal output andanalog signal output, respectively.

Copy control information 314 (APS; Analog Protection System) controlscopying to an analog recording device. A psuedo-sink pulse may be addedto an analog video signal for the purpose of controllingpermission/inhibition of copying.

Move mode 315 is information concerning permission/inhibition of “move”.The term “move” means that information is copied onto a different mediumand thereafter, a counterpart of that information recorded on theoriginal medium is erased. This ensures that only one copied informationpiece can always be allowed to exist, making it possible to keep thecondition that many repetitive copying operations result insubstantially one copying operation. When information subject to “copyone generation” is copied in the normal copy mode, any more copying isprevented by changing the copy control information to “no more copies”but when the move mode proceeds, the copy control information is againreturned to “copy one generation” so that the information of interestcan be sent to the copying destination to enable the sent information tobe copied and after the copying, the original information is erased. Themove mode 315 may prescribe the move permission count in addition to themove permission. In that case, the move permission count information maybe decremented each time that a move operation is carried out. Forexample, when the move mode 315 is of 4 bits, the permission countranging from 0 to 15 can be defined. In this case, the definition may besuch that even when all of the 4 bits are “1111”, the count is not 15but is infinite.

Playback count 316 is for prescribing the playback permission count andis ruled as necessary. The playback count is used when, for example, inaddition to a limit set to the effective period by the aforementionedretention period, the playback count is desired to be limited. Like themove permission count, the playback permission count is decremented eachtime that one playback operation is carried out. When all of the bitsare “1” initially, the limitation to the count can be handled as beingnullified.

Playback longevity period 317 is used when the playback operation islimited temporally. For example, when the playback longevity period isof 16 bits to ensure management in a unit of minute, temporal limitationup to about 45 days can be available. For all of the bits being “1”,this period can also be handled as designating unlimitedness. If theCGMS 313 is “copy never”, the rules in the aforementioned playbackpermission period for instance are predominant in connection with thetemporal limitation to the playback operation. Accordingly, the rules inthe playback longevity period 317 are used as information available inan instance excepting the above. In an alternative, the playbacklongevity period 317 may be incorporated into the playback permissionperiod so as to be handled as unified information.

Pause period 318 prescribes a period for permitting a pause operation(temporary stop). The pause period can be handled similarly to theplayback longevity period 317. More particularly, it happens thatplayback operation is required to be stopped temporarily on urgentbusiness due to a visitor. In such a case, the pause period is used totemporally limit the temporary stop.

Delayed start time 319 is used, to limit time for starting working.While the aforementioned retention period sets a limit to working,starting with the recording time, the delayed start time 319 permitsworking, starting with absolute time such as 12.00 p.m., Jan. 1, 2001for instance. This is suitable to permit simultaneous disclosures at atime. After the delayed start period has elapsed, information ispermitted for playback and delivery for instance. As the delayed starttime, the absolute time may be described or a difference time (relativetime) from a time (for example, 12.00 p.m., Jan. 1, 1970) agreed bypersons in the same line of business may be described. If all of thebits are “0”, the recording time may be the start time.

Not all contents of the copy control information 304 are necessary andsome of the contents can be omitted. Further, move permissible period307B to be described later may arranged, for example, between the movemode 315 and the playback count 316, instead of being positioned asshown in FIG. 8.

The recording time 305 in FIG. 8 records, for example, the time of theclock 107 of FIG. 4 or the time supplied from the service informationapplying circuit 36 of FIG. 2. The recording time 305 can be recorded ina unit of sector for instance.

In the present embodiment, information covering retention period 306A,copy permission period 306B, playback permission period 307A and movepermission period 307B is further used. All of the information can beused but only two of 306A and 307A, only two of 306B and 307B or onlyone of, for example, 306B may sometimes be used.

For the information “copy never”, the copyright holder or the softwareproducer rules the retention period 306A and the playback permissionperiod 307A as described previously. For example, the retention periodis set to 9 hours and the playback permission period is set to 2 hours.When there is no need of setting a limit to the period, a code of “nolimit” may be applied. In addition to the above, limitation to theplayback count may be prescribed.

For the information “copy one generation”, the copy permission period306B and move permission period 307B are ruled used similarly and thelatter is applied only when needed. Also, limitation to the movepermission count may be prescribed.

User identification information 308 is recorded when a code inherent toa user is used with the aim of permitting information recorded on themedium to be reproduced by only the same apparatus as that used duringrecording or only the user. Encryption information 309 is used to decodea cipher during playback when information is encrypted and recorded onthe recording medium. This will be described again later with referenceto FIGS. 12 and 13. The information per se has a large amount of dataand therefore, code numbers may be recorded and informationcorresponding to a code number stored in advance may be drawn out bymeans of the reproducing apparatus so as to be used. The information asabove is recorded as necessary at a relatively short temporal pitch, forexample, every image frame or at the rate of predetermined amount ofdata. With the control signal having the structure as above, the presentinvention can be practiced but the structure shown in FIG. 8 is forexplanation only and various kinds of structure, recording position onthe medium and frequency can also be applicable.

FIG. 10 is a block diagram showing a structure of a second controlsignal recorded during reproduction in the present embodiment. Thesecond control information includes playback start time 321, playbackstart sector number 322 and playback stop sector number 323. Theplayback start time 321 records a time counted by, for example, theclock 107 of FIG. 12 to be described later. When a playback is stopped,a sector number at that position is recorded in the playback stop sectornumber 323. Since playback times at sectors on the way can be calculatedfrom the playback start time 321, playback times at all sectors subjectto reproduction can be known. Of course, the playback time can berecorded in a unit of sector.

In the case of the tape medium for instance, when the operation mode isreturned to the stop mode during playback, individual pieces of controlinformation shown in FIG. 10 can be recorded anywhere near the stopposition. The information can also be recorded using, for example, therecording circuit of FIG. 4.

Referring to FIG. 11, the recording position of the control signal onthe medium will be described. FIG. 11 diagrammatically shows recordingpositions of the control signal and information data such as video andaudio data on the recording medium. Recording positions shown at (a) inFIG. 11 are suitable for the tape medium. In this case, the block of thecontrol signal is preferably provided, for example, every recordingtrack. Accordingly, in each track, a block of the control signal isarranged in the header part, for instance, to precede the informationsuch as video and audio data. Recording positions shown at (b) in FIG.11 are suitable for a digital video disc. In this case, the controlsignal and video and audio data are preferably provided every sectorhaving a certain amount of information. Accordingly, they are arrangedat the header part every sector. Recording positions shown at (c) inFIG. 11 are suitable for a hard disc. In this case, the information suchas video and audio data and the control signal are recorded at positionsspaced apart from each other on the disc to permit the whole of thecontrol signal to be read within a short period of time during start. Inan alternative, the first control information may be recorded at theheader part and the second control information may be recorded at aposition spaced apart therefrom. Since the second control information isto be recorded or rewritten during reproduction, it is required to berecorded at an independent or isolated position. Alternatively, insteadof being recorded in the recording medium, the second controlinformation may be recorded in, for example, the memory device or memorycircuit 104 mounted externally of the recording medium or in a memorydevice in an independent apparatus.

Referring now to FIGS. 12 and 13, another embodiment directed to thereproducing circuit 1 and the recording circuit 2. FIG. 12 is a blockdiagram showing a reproducing circuit 1 according to the presentembodiment and FIG. 13 is a block diagram showing a recording circuit 2according to the present embodiment. Constituent components identical tothose in FIGS. 6 and 4 are designated by identical reference numeralsand will not be detailed. The present embodiment is effective when it isrequired that only predetermined users be allowed to take part inplayback or when a fee is charged.

In FIG. 12, there are provided a decryption circuit 131 and an inputterminal 132 for an identification code inherent to the apparatus and inFIG. 13, there are provided an encryption circuit 233 and an inputterminal 234 for an identification code inherent to the apparatus or anapparatus permitted for playback.

In the encryption circuit 233 of FIG. 13, encryption is carried out withthe identification code of the apparatus fed from the input terminal234. Without performing descramble in the RF tuner 5, two kinds ofencryption may be carried out in an overlap fashion. In the decryptioncircuit 131 of FIG. 12, decryption is carried out with theidentification code of the apparatus fed from the input terminal 132. Ifthe identification code is not an authorized one, normal decryptionfails to proceed to thereby prevent the playback from being done.

In the apparatus, encryption with the identification code is exemplifiedbut this code may be added to the aforementioned block of the controlsignal and may be detected on the reproducing side to decide whether thedelivery of signal is permissible.

Encryption may be done in a unit of program but when the encryption iscarried out while changing the key to the encryption in a unit of sectorand individual keys are recorded, an encryption process can be performedin the unit of sector.

Next, an example of operation of controlling the retention period 306Aand playback permission period 307A during reproduction will bedescribed. Firstly, when the difference between recording time 305 of asector to be reproduced and the present time indicated by the clock 107is within the retention period 306A at the initiation of a playback, theplayback is started. At the same time, the playback start time 321 andplayback start sector number 322 are recorded as the second controlinformation. With the playback stopped, a playback stop sector number323 is recorded. With a pause taken, a playback stop sector number 323is recorded as in the case of the stoppage of the playback and with thepause released, a process similar to that at the initiation of theplayback is carried out. More particularly, the time is again confirmedand if the time is within the retention period 306A, playback resumes.When backward feed is done, a playback time at that location isconfirmed and if the difference between the playback time and thepresent time is within the playback permission period 307A, a playbackis permitted. When fast feed is carried out, it can be known byconfirming the second control information that no playback is carriedout throughout a fast feed range. Therefore, when a playback isinitiated, permission/inhibition of the playback is decided by only theretention period 306A regardless of the playback permission period 307A.Namely, a playback longevity period after one playback operation subjectto the playback permission period 307A is controlled for a playbacklongevity period following recording subject to the retention period 6A.

The pause period can also be controlled depending on the playbackpermission period 307A. In this case, permission/inhibition of theinitial playback start is controlled by the retention period 306A andwhen a playback stop is carried out or a pause is taken after start ofthe playback, the period for stoppage is measured in order thatresumption of playback is permitted when the measured period is withinthe playback permission period 307A but resumption of playback isinhibited when the measured period exceeds the playback permissionperiod 307A. Further, by inhibiting the backward feed, it is possible tosteadily permit only one playback operation. In this case, control canbe undertaken without recording the second control information.

In case information under the control of the retention period 306A orplayback permission period 307A is reproduced and then delivered as adigital signal from the output terminal 113, it is conceivable that theretention period 306A or playback permission period 307A of controlinformation added to the information of interest is decremented orzeroed.

Operation when the copy permission period 306A and move permissionperiod 307B are used is as follows. Firstly, if the difference between arecording time 305 of a sector to be reproduced and the present timeindicated by the clock 107 is within the copy permission period 306B atthe playback initiation, normal playback is started and a reproductionsignal for copying is delivered to the outside. Since the copy controlinformation “copy one generation” remains intact in the signalreproduced and delivered to the outside, recording is permissible forthe external device. During recording, however, the copy controlinformation is rewritten to “no more copies” and as a result, any morecopying is prevented. In case a playback stop is carried out or a pauseis taken after start of the playback, if the copy permission period hasalready expired at the time that the playback resumes, the copy controlinformation can be changed to, for example, “no more copy” so as toinhibit copying. As far as one copy operation is concerned, the playbackmay proceed to the end with the copy control information kept to be“copy one generation” and copying may be permitted.

More particularly, a copy longevity period after recording subject tothe copy permission period 306B is controlled. After the copy permissionperiod has expired, another recording apparatus is allowed to moveinformation to another medium on the premise that the originalinformation is erased. If expiration of the copy permission period isdetected through the aforementioned method at the start of playback,information having its copy control information rewritten to “no morecopies” is added with information of move permission period 307B asnecessary and then moved to the external recording apparatus. Theoriginal information is erased from the medium through a method to bedescribed later. Thereafter, if the difference between the recordingtime 305 and the present time indicated by the clock 107 is within themove permission period 307B, move between the media is permissible. Whenthe move permission period expires, it is impossible to perform move anymore. In the absence of the move permission period 307B, the period formove is unlimited. In other words, the move permission period after thecopy permission period has stopped or expired is controlled by the movepermission period 307B.

As set forth so far, in copying information to the external recordingapparatus within the copy permission period, the copy controlinformation on the original recording medium is changed from “copy onegeneration” to “no more copies” as the copying operation proceeds. But,the copy control information can be changed at the end of the copypermission period to permit preparation of a plurality of sheets of copyof one generation.

There are some methods of managing the permission/inhibition of deliveryof the information to be reproduced (playback, copy or move) in a unitof time. The managing method entangles the method of recording theaforementioned control signal. If the retention period and the playbackpermission period or copy permission period are managed every image,that is, every frame, the most stringent management can be carried out.The management per frame, however, imposes a large load on operation ofhardware, involving a problem of erase to be described later.Accordingly, by managing the control signal in a unit of certain time,the load imposed on processing can be alleviated. For example, atolerance of one minute is set up for control of the retention period306A or playback permission period 307A. Then, for a retention period306A of 120 minutes or a playback permission period 307A of 120 minutes,control is allowed to be done between 120 minutes and 121 minutes andthe management can be performed every minute. The tolerance may be setup in a unit of predetermined number of images or in a unit ofpredetermined amount of data.

The move count and the playback count indicated in connection with FIG.9 can be managed as will be described below.

In the case of move, the count is decremented by one in essential eachtime that the move operation is carried out once and a reproductionsignal is sent to the external recording apparatus. If, while the numberis prescribed, the copy control information signal designates “no morecopies”, the copy control information can be changed to “copy onegeneration” and delivered and when recording is carried out with theexternal recording apparatus, the copy control information can bechanged to “no more copies”. Further, only when the external recordingapparatus is adapted to move from the standpoint of erase operation tobe described later, the count can be decremented by one and thendelivered. Contrarily, in the case of the apparatus unadapted to move,the count can be rewritten to 0 and then the control signal can bedelivered, thus disabling any more move. Obviously, the apparatus on thereproduction signal transmitting side must have the erase functionconforming to move as will be described later. A control signalindicative of the erase function may be transmitted to the externalrecording apparatus.

On the other hand, in the case of the playback count, the manner ofmanagement of the playback count matters in the event that, for example,an interruption occurs on the way of playback. A method is availableaccording to which the management is carried out in a unit of contentsand after playback has proceeded for a constant time, the count isdecremented by one. Alternatively, at the time that a stop, putting apause aside, is applied, the count may be decremented by one. Further,at the time that backward feed of the medium, putting a stop aside, isapplied, the count may be decremented by one.

A description concerning the playback longevity period 317 will begiven. When, during playback operation, the playback permission periodstops or ends before the program comes to an end, the reproductionoutput operation can be inhibited but otherwise, delivery of thereproduction output can continue to the end unless the playbackoperation is stopped. In the latter case, one playback operation can becarried out unless the playback longevity period has already expired atthe time that the playback starts. Information for the above purposescan be detected during playback by means of the information detectioncircuit 111 of FIG. 6. The information can be rewritten by means of, forexample, the signal output circuit 106 of FIG. 6. This can furtherpromote the working condition management.

Next, a method of erasing the information on the medium will bedescribed. The term “erase” referred to herein not only signifies eraseliterally but also involves the case of rewriting at least part of theinformation on the medium to disable the effective information to bereproduced. Only the aforementioned effective period management in thereproducing circuit is sometimes insufficient to be versatile in thefuture. If the medium recorded with the information remains, then thereproducing playback will be impossible at present but there is a fearof the future advent of a method that overcomes the present-daypreventive method to make playback possible. From the above point ofview, the information on the medium is erased after playback or at thetermination of the retention period 306A and playback permission period307A, thus further promoting safety. In addition, when theaforementioned move mode is carried out, the information on the mediummust be erased after copying.

Firstly, a unit of information to be erased is considered. It is firstconceivable that when the period runs out, an erase operation is carriedout in a unit of frame. It is also conceivable that the information ismanaged in a unit of larger time. For example, the management at therate of one minute is carried out and information confined within oneminute until the expiration is erased collectively. Alternatively, themanagement is carried out in a unit of plural image frames andinformation confined within a prescribed time until the expiration maybe erased collectively. A similar operation may be undertaken at therate of predetermined amount of data.

Timing of erase will be considered. As described above, the method isavailable according to which the erase timing linking to the retentionperiod and playback permission period in some ways is determined. Inaddition to this, it is conceivable that when information once subjectedto playback is not permitted for repetitive playback, the information iserased at a timing of playback even if the playback timing far precedesthe effective period. In the event that the medium is removed form theapparatus at the expiration of the period and erase cannot be fulfilled,erase operation may be carried out when the medium is mountedsubsequently.

In the case of move, too, it is conceivable that information moved tothe next medium is erased in a unit of frame. Alternatively, theinformation may be managed in a unit of larger time. For example, whenthe information is managed every minute, information confined within oneminute after move may be erased collectively. In an alternative, theinformation may be managed in a unit of plural image frames andinformation confined within a prescribed time may be erasedcollectively. A similar operation may be performed at the rate ofpredetermined amount of data. Further, after one program has completedcopying to the next medium, the whole of the program may be erasedcollectively.

Next, practical erase operation will be described with reference to thedrawings. Erase is made in different ways depending on the type of themedium. An example applied to a disc medium will first be described withreference to FIG. 14.

FIG. 14 is a block diagram showing another embodiment of the informationreproducing apparatus according to the invention. In the presentembodiment, the block diagram of the reproducing circuit shown in FIG. 6is unified with the block diagram of the circuit shown in FIG. 4,additionally having a media type detection circuit 207. Obviously, thereproducing circuit construction as shown in FIG. 7 or 12 can be used inplace of the FIG. 6 reproducing circuit.

FIG. 14 is adapted to a disc medium. The disc medium is sorted into anRW (or RAM) type capable of rewriting records many times and an R typeincapable of rewriting information once recorded. The term“un-rewritable” means “un-erasable” and if erase is to be applied ormove is to be carried out after the expiration of the presupposedeffective period, recording onto the R type disc medium must be rejectedinitially. The media type detection circuit 207 is provided for thispurpose. Thus, on the premise that the R type disc is carried and eraseis made or move is carried out after the expiration of the effectiveperiod, a control signal is sent to the recording signal processingcircuit 203 to prevent delivery of a code to be recorded. For detectionof the medium, some methods have been known which are directed toreading a sign applied outside a recording area of the medium, reading acode precedently recorded at part of the recording area and making adecision on the basis of reflection factor, respectively.

The output of the output control circuit 112 on the reproducing side isalso fed to the recording signal processing circuit 203. On the basis ofthe previously-described retention period and playback permission periodor at the time that move proceeds, the output control circuit 112generates a control signal for commanding an erase operation. Responsiveto this control signal, the recording signal processing circuit 203generates a code for performing erase at a location of interest on themedium. This code can be a code that is meaningless as information. Asdescribed previously, the method is available which manages data in aunit of frame and erases the whole of data. This method is, however,sometimes unpractical from the viewpoint of the time for processing.Even in the case of the management in a unit of frame, the object can beattained sufficiently by erasing only the control signal part as shownin FIG. 8 for instance or especially erasing only the encryptioninformation 309 in the control signal part.

This holds true for the management in a unit of other than the frame,for example, for the management in a unit of time, in a unit of group ofimages or in a unit of prescribed amount of data. For example, when theinformation is managed in a unit of minute, data confined within oneminute until the expiration of the effective period or a control signalof data within one minute after move can be erased. In case encryptedinformation is recorded, a method is available which erases onlyscramble information.

Further, in case the control signal in the unit to be managed is, forexample, encrypted, the scramble information is recorded collectively ata single location on the medium. This information is reproducedcollectively during reproduction inclusive of move, stored at aspecified location in the memory circuit 104 and erased from the medium.If the reproduction is stopped on the way, an operation for recordingagain a control signal for a portion not played back onto the medium iscarried out to simplify the erase process. In this case, for the sake ofpreventing the control signal from being collapsed owing to powerfailure on the way, the whole or at least part of the area for storageof the information in the memory circuit 104 may preferably beimplemented with a non-volatile memory circuit such as a flash memory.Especially, in the case of move, the whole of the program may be erasedcollectively through the method as above after the move operation hasstopped.

Obviously, a unit dedicated to reproduction such as a CD-ROM drive doesnot have the recording circuit block corresponding to the lower half inFIG. 14 but if having a component corresponding to the recording signalprocessing circuit 203 having the function of generating the code forerase, it can operate similarly in terms of circuitry. An apparatususing a hard disc as recording medium can of course dispense with theaforementioned media type detection circuit 207.

Next, FIG. 15 is a block diagram showing another embodiment of theinformation reproducing apparatus according to the invention. In thepresent embodiment, an erasing device 115 is added to the block diagramof the reproducing circuit shown in FIG. 6. The reproducing circuitconstruction in FIG. 7 or 12 can of course substitute for the circuitshown in FIG. 6.

The FIG. 15 embodiment is suitable for the tape medium. When theretention period and playback permission period are ruled and a portiononce played back cannot be fed backward or when move is carried out,information on the tape medium is to be erased during reproduction. Theerasing device 115 is for this purpose and practically implemented withan erase head. During reproduction, the output control circuit 112 sendsa control signal to the erasing device 115 to decide whether an eraseoperation is performed. For example, when the retention period andplayback permission period are prescribed, an erase operation issometimes carried out following reproduction. As the erasing device 115,a full erase head fixed to a tape running mechanism, a flying erase headcarried on the rotary drum also carrying the video head or another videohead not used as reproducing head in the playback mode as described inJP-A-7-244924.

If the full erase head is used, it must be mounted to a position forerase after scanning of the video head in contrast to the normalposition. If the flying erase head or an unused video head is used asthe erasing device, it must also be mounted to a position succeeding thereproducing head in the course of tape scanning. In the latter case, ifthe mount position satisfies the above condition accidentally but if notso, the height must be changed. Even in the former case, it is necessaryto change the height or to mount another head.

In any methods, the information to be recorded is digital informationand differing from analog information, any problem in quality does notarise when erase is carried out using a DC magnetic field without usingan AC magnetic field. Practically, when erase is carried out whileperforming reproduction, interference due to magnetic induction from theerase head to the reproducing head is difficult to prevent. But thisproblem can be solved using DC. Conceivably, the erasing device can beconstructed of a permanent magnet. But, a mechanism is needed whichmoves the location when the erase operation is not done and besidestension applied to the tape changes depending on whether or not erase iscarried out, thereby raising a problem that the mechanism is difficultto control. In such an event, the aforementioned head may preferably beused as an electromagnet.

As described above, according to the invention, the information to whicha stringent copy limit is set can be recorded temporarily by prescribingthe retention period and playback permission period. Further, since theplayback period is limited, the copyright holders can protect theirright. In other words, compatibility between profits of the user and thecopyright holder can be met. Further, by erasing the information whenthe period expires, security against unauthorized copying can be assuredto advantage. In addition, the information can be erased collectively ina unit of time or data amount or only specified part of the recordinginformation can be erased to simplify the erase process to advantage.

Furthermore, even the information subject to copy limitation of “copyone generation” can be limited temporally by prescribing the copypermission period and therefore, uneasiness of the copyright holderscaused by keeping “copy one generation” intact for a long time can beeliminated. Even when the control information changes to “no morecopies”, by introducing the move mode on the premise that theinformation on the original medium is erased, the user can convenientlyexchange the medium even under the condition that the medium used forcopying is only one. As necessary, the move permission period canadvantageously be limited.

Furthermore, by erasing the information collectively in a unit of timeor amount of data or erasing specified part of the recordinginformation, the erase process can advantageously be simplified. Inaddition, by limiting the move count, playback count and playbacklongevity period, the management of working conditions can further bepromoted.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed is:
 1. A reproducing system, comprising: a receiverconfigured to receive an audio/video information encrypted according toa predetermined encryption method and control information related to theaudio/video information, the control information for controllingreproduction of the audio/video information after distribution and at alocation different from a distribution location; a memory configured toat least temporarily store at least a portion of the audio/videoinformation and at least a portion of the control information; adetector configured to detect at least a portion of the controlinformation, including data indicative of a first period for enabling areproduction of the audio/video information and disabling reproductionafter expiration of a prescribed time and a second period, that beginsat a start of an initial reproduction of the audio/video informationwithin the first period and is shorter than the first period, forenabling a reproduction of the audio/video information and disablingreproduction after expiration of a prescribed time following the startof the initial reproduction of the audio/video information; a decryptorconfigured to decrypt the audio/video information encrypted according tothe predetermined encryption method; a reproducer configured toreproduce at least a portion of the audio/video information from thememory consistent with restrictions associated with the first period andthe second period through decryption by the decryptor; and a controllerconfigured to control at least the reproducer, wherein, in a case wherethe controller confirms that an elapsed time from a start of the firstperiod is within the first period and an elapsed time from a start of aninitial reproduction of the audio/video information is within the secondperiod, the controller is configured to, based on at least a portion ofthe control information detected by the detector, allow the reproducerto reproduce the audio/video information, wherein, in a case where thecontroller confirms that a reproduction of the audio/video informationis started before an end of the first period and the reproduction iscontinuing at the end of the first period, the controller is configuredto, based on at least a portion of the control information detected bythe detector, allow the reproducer to reproduce the audio/videoinformation to an end of the audio/video information beyond the end ofthe first period and thereafter not allow the reproducer to start ananother reproduction of the audio/video information even if an elapsedtime from a start of an initial reproduction of the audio/videoinformation is within the second period.
 2. The reproducing systemaccording to claim 1, wherein the audio/video information is embeddedwith at least a portion of the control information.
 3. The reproducingsystem according to claim 1, wherein the control information is embeddedas a watermark in the audio/video information.
 4. The reproducing systemaccording to claim 1, wherein the control information includes dataindicative of user identification information for permitting a specifieduser to reproduce the audio/video information.
 5. The reproducing systemaccording to claim 1, wherein the reproduction to the end of theaudio/video information beyond the end of the first period is enabled ifthe reproduction is not stopped.
 6. The reproducing system according toclaim 1, wherein the memory is configured to keep storing theaudio/video information after the end of the first period, and a startof a reproduction is disabled after the end of the first period.
 7. Areproducing system, comprising: a receiver configured to receive anaudio/video information which is encrypted according to a predeterminedencryption method and is restricted from reproduction based on at leasta portion of control information, including data indicative of a firstperiod for enabling a reproduction of the audio/video information anddisabling reproduction after expiration of a prescribed time and asecond period, that begins at a start of an initial reproduction of theaudio/video information within the first period and is shorter than thefirst period, for enabling a reproduction of the audio/video informationand disabling reproduction after expiration of a prescribed timefollowing the start of the initial reproduction of the audio/videoinformation; a decryptor configured to decrypt the audio/videoinformation encrypted according to the predetermined encryption methodand received by the receiver; a reproducer configured to reproduce atleast a portion of the audio/video information consistent withrestrictions associated with the first period and the second periodthrough decryption by the decryptor; and a controller configured tocontrol at least the reproducer, wherein, in a case where the controllerconfirms that an elapsed time from a start of the first period is withinthe first period and an elapsed time from a start of an initialreproduction of the audio/video information is within the second period,the controller is configured to, based on at least a portion of thecontrol information, allow the reproducer to reproduce the audio/videoinformation, wherein, in a case where the controller confirms that areproduction of the audio/video information is started before an end ofthe first period and the reproduction is continuing at the end of thefirst period, the controller is configured to, based on at least aportion of the control information, allow the reproducer to reproducethe audio/video information to an end of the audio/video informationbeyond the end of the first period and thereafter not allow thereproducer to start an another reproduction of the audio/videoinformation even if an elapsed time from a start of an initialreproduction of the audio/video information is within the second period.8. The reproducing system according to claim 7, wherein the controlinformation includes data indicative of user identification informationfor permitting a specified user to reproduce the audio/videoinformation.
 9. The reproducing system according to claim 7, wherein thereproduction to the end of the audio/video information beyond the end ofthe first period is enabled if the reproduction is not stopped.
 10. Atransmitting system, comprising: a receiver configured to receive arequest of a user; a transmitter configured to transmit an audio/videoinformation to an external reproducing system in response to the requestof the user, wherein the audio/video information is encrypted accordingto a predetermined encryption method and is restricted from reproductionbased on at least a portion of control information, including dataindicative of a first period for enabling a reproduction of theaudio/video information and disabling reproduction after expiration of aprescribed time and a second period, that begins at a start of aninitial reproduction of the audio/video information within the firstperiod and is shorter than the first period, for enabling a reproductionof the audio/video information and disabling reproduction afterexpiration of a prescribed time following the start of the initialreproduction of the audio/video information; wherein at least a portionof the control information is for controlling a reproduction of theexternal reproducing system, in a case where an elapsed time from astart of the first period is within the first period and an elapsed timefrom a start of an initial reproduction of the audio/video informationis within the second period, to allow the reproduction of theaudio/video information by the external reproducing system, and, in acase where a reproduction of the audio/video information by the externalreproducing system is started before an end of the first period and thereproduction is continuing at the end of the first period, to allow thereproduction to an end of the audio/video information beyond the end ofthe first period and thereafter not allow a start of an anotherreproduction of the audio/video information even if an elapsed time froma start of an initial reproduction of the audio/video information iswithin the second period.
 11. The transmitting system according to claim10, wherein the transmitter is configured to transmit the audio/videoinformation with at least a portion of the control information relatedto the audio/video information to the external reproducing system. 12.The transmitting system according to claim 11, wherein at least aportion of the control information to be transmitted by the transmitteris embedded as a watermark in the encrypted audio/video information. 13.The transmitting system according to claim 10, wherein the controlinformation includes data indicative of user identification informationfor permitting a specified user to reproduce the audio/videoinformation.
 14. The transmitting system according to claim 10, wherein,in a case that the audio/video information is reproduced once by theexternal reproducing system and thereafter moved to another externalreproducing system, a reproduction of the audio/video information movedto the other external reproducing system is restricted based on a periodwhich is decremented from at least one of the first period or the secondperiod.
 15. The transmitting system according to claim 10, furthercomprising an encryptor configured to encrypt the audio/videoinformation in advance of transmitting to the external reproducingsystem.
 16. A reproducing system, comprising: a receiving means forreceiving an audio/video information encrypted according to apredetermined encryption method and control information related to theaudio/video information, the control information for controllingreproduction of the audio/video information after distribution and at alocation different from a distribution location; a storing means for atleast temporarily storing at least a portion of the audio/videoinformation and at least a portion of the control information; adetecting means for detecting at least a portion of the controlinformation, including data indicative of a first period for enabling areproduction of the audio/video information and disabling reproductionafter expiration of a prescribed time and a second period, that beginsat a start of an initial reproduction of the audio/video informationwithin the first period and is shorter than the first period, forenabling a reproduction of the audio/video information and disablingreproduction after expiration of a prescribed time following the startof the initial reproduction of the audio/video information; a decryptingmeans for decrypting the audio/video information encrypted according tothe predetermined encryption method; a reproducing means for reproducingat least a portion of the audio/video information from the memoryconsistent with restrictions associated with the first period and thesecond period through decryption by the decrypting means; and acontrolling means for controlling at least the reproducer, wherein, in acase where the controlling means confirms that an elapsed time from astart of the first period is within the first period and an elapsed timefrom a start of an initial reproduction of the audio/video informationis within the second period, the controlling means is configured to,based on at least a portion of the control information detected by thedetecting means, allow the reproducing means to reproduce theaudio/video information, wherein, in a case where the controlling meansconfirms that a reproduction of the audio/video information is startedbefore an end of the first period and the reproduction is continuing atthe end of the first period, the controlling means is configured to,based on at least a portion of the control information detected by thedetecting means, allow the reproducing means to reproduce theaudio/video information to an end of the audio/video information beyondthe end of the first period and thereafter not allow the reproducingmeans to start an another reproduction of the audio/video informationeven if an elapsed time from a start of an initial reproduction of theaudio/video information is within the second period.
 17. The reproducingsystem according to claim 16, wherein the audio/video information isembedded with at least a portion of the control information.
 18. Thereproducing system according to claim 16, wherein the controlinformation is embedded as a watermark in the audio/video information.19. The reproducing system according to claim 16, wherein the controlinformation includes data indicative of user identification informationfor permitting a specified user to reproduce the audio/videoinformation.
 20. The reproducing system according to claim 16, whereinthe reproduction to the end of the audio/video information beyond theend of the first period is enabled if the reproduction is not stopped.21. The reproducing system according to claim 16, wherein the storingmeans keeps storing the audio/video information after the end of thefirst period, and a start of a reproduction is disabled after the end ofthe first period.
 22. A reproducing system, comprising: a receivingmeans for receiving an audio/video information which is encryptedaccording to a predetermined encryption method and is restricted fromreproduction based on at least a portion of control information,including data indicative of a first period for enabling a reproductionof the audio/video information and disabling reproduction afterexpiration of a prescribed time and a second period, that begins at astart of an initial reproduction of the audio/video information withinthe first period and is shorter than the first period, for enabling areproduction of the audio/video information and disabling reproductionafter expiration of a prescribed time following the start of the initialreproduction of the audio/video information; a decrypting means fordecrypting the audio/video information encrypted according to thepredetermined encryption method and received by the receiving means; areproducing means for reproducing at least a portion of the audio/videoinformation consistent with restrictions associated with the firstperiod and the second period through decryption by the decrypting means;and a controlling means for controlling at least the reproducing means,wherein, in a case where the controlling means confirms that an elapsedtime from a start of the first period is within the first period and anelapsed time from a start of an initial reproduction of the audio/videoinformation is within the second period, the controlling means isconfigured to, based on at least a portion of the control information,allow the reproducing means to reproduce the audio/video information,wherein, in a case where the controlling means confirms that areproduction of the audio/video information is started before an end ofthe first period and the reproduction is continuing at the end of thefirst period, the controlling means is configured to, based on at leasta portion of the control information, allow the reproducing means toreproduce the audio/video information to an end of the audio/videoinformation beyond the end of the first period and thereafter not allowthe reproducing means to start an another reproduction of theaudio/video information even if an elapsed time from a start of aninitial reproduction of the audio/video information is within the secondperiod.
 23. The reproducing system according to claim 22, wherein thecontrol information includes data indicative of user identificationinformation for permitting a specified user to reproduce the audio/videoinformation.
 24. The reproducing system according to claim 22, whereinthe reproduction to the end of the audio/video information beyond theend of the first period is enabled if the reproduction is not stopped.25. A transmitting system, comprising: a receiving means for receiving arequest of a user; a transmitting means for transmitting an audio/videoinformation to an external reproducing system in response to the requestof the user, wherein the audio/video information is encrypted accordingto a predetermined encryption method and is restricted from reproductionbased on at least a portion of control information, including dataindicative of a first period for enabling a reproduction of theaudio/video information and disabling reproduction after expiration of aprescribed time and a second period, that begins at a start of aninitial reproduction of the audio/video information within the firstperiod and is shorter than the first period, for enabling a reproductionof the audio/video information and disabling reproduction afterexpiration of a prescribed time following the start of the initialreproduction of the audio/video information; wherein at least a portionof the control information is for controlling a reproduction of theexternal reproducing system, in a case where an elapsed time from astart of the first period is within the first period and an elapsed timefrom a start of an initial reproduction of the audio/video informationis within the second period, to allow the reproduction of theaudio/video information by the external reproducing system, and, in acase where a reproduction of the audio/video information by the externalreproducing system is started before an end of the first period and thereproduction is continuing at the end of the first period, to allow thereproduction to an end of the audio/video information beyond the end ofthe first period and thereafter not allow a start of an anotherreproduction of the audio/video information even if an elapsed time froma start of an initial reproduction of the audio/video information iswithin the second period.
 26. The transmitting system according to claim25, wherein the transmitting means is configured to transmit theaudio/video information with at least a portion of the controlinformation related to the audio/video information to the externalreproducing system.
 27. The transmitting system according to claim 25,wherein at least a portion of the control information to be transmittedby the transmitter is embedded as a watermark in the encryptedaudio/video information.
 28. The transmitting system according to claim25, wherein the control information includes data indicative of useridentification information for permitting a specified user to reproducethe audio/video information.
 29. The transmitting system according toclaim 25, wherein, in a case that the audio/video information isreproduced once by the external reproducing system and thereafter movedto another external reproducing system, a reproduction of theaudio/video information moved to the other external reproducing systemis restricted based on a period which is decremented from at least oneof the first period or the second period.
 30. The transmitting systemaccording to claim 25, further comprising an encrypting means forencrypting the audio/video information in advance of transmitting to theexternal reproducing system.
 31. A method, comprising: receiving anaudio/video information encrypted according to a predeterminedencryption method and control information related to the audio/videoinformation by a receiver, the control information for controllingreproduction of the audio/video information after distribution and at alocation different from a distribution location; at least temporarilystoring at least a portion of the audio/video information and at least aportion of the control information in a memory; detecting by a detectorat least a portion of the control information, including data indicativeof a first period for enabling a reproduction of the audio/videoinformation and disabling reproduction after expiration of a prescribedtime and a second period, that begins at a start of an initialreproduction of the audio/video information within the first period andis shorter than the first period, for enabling a reproduction of theaudio/video information and disabling reproduction after expiration of aprescribed time following the start of the initial reproduction of theaudio/video information; decrypting the audio/video informationencrypted according to the predetermined encryption method by adecryptor; reproducing by a reproducer at least a portion of theaudio/video information from the memory consistent with restrictionsassociated with the first period and the second period throughdecryption by the decryptor; and controlling at least the reproducer bya controller, wherein, in a case where the controller confirms that anelapsed time from a start of the first period is within the first periodand an elapsed time from a start of an initial reproduction of theaudio/video information is within the second period, the controller isconfigured to, based on at least a portion of the control informationdetected by the detector, allow the reproducer to reproduce theaudio/video information, wherein, in a case where the controllerconfirms that a reproduction of the audio/video information is startedbefore an end of the first period and the reproduction is continuing atthe end of the first period, the controller is configured to, based onat least a portion of the control information detected by the detector,allow the reproducer to reproduce the audio/video information to an endof the audio/video information beyond the end of the first period andthereafter not allow the reproducer to start an another reproduction ofthe audio/video information even if an elapsed time from a start of aninitial reproduction of the audio/video information is within the secondperiod.
 32. The method according to claim 31, wherein the audio/videoinformation is embedded with at least a portion of the controlinformation.
 33. The method according to claim 31, wherein the controlinformation is embedded as a watermark in the audio/video information.34. The method according to claim 31, wherein the control informationincludes data indicative of user identification information forpermitting a specified user to reproduce the audio/video information.35. The method according to claim 31, wherein the reproduction to theend of the audio/video information beyond the end of the first period isenabled if the reproduction is not stopped.
 36. The method according toclaim 31, wherein the memory is configured to keep storing theaudio/video information after the end of the first period, and a startof a reproduction is disabled after the end of the first period.
 37. Amethod, comprising: receiving by a receiver an audio/video informationwhich is encrypted according to a predetermined encryption method and isrestricted from reproduction based on at least a portion of controlinformation, including data indicative of a first period for enabling areproduction of the audio/video information and disabling reproductionafter expiration of a prescribed time and a second period, that beginsat a start of an initial reproduction of the audio/video informationwithin the first period and is shorter than the first period, forenabling a reproduction of the audio/video information and disablingreproduction after expiration of a prescribed time following the startof the initial reproduction of the audio/video information; decryptingby a decryptor the audio/video information encrypted according to thepredetermined encryption method and received by the receiver;reproducing by a reproducer at least a portion of the audio/videoinformation consistent with restrictions associated with the firstperiod and the second period through decryption by the decryptor; and acontrolling at least the reproducer, wherein, in a case where thecontroller confirms that an elapsed time from a start of the firstperiod is within the first period and an elapsed time from a start of aninitial reproduction of the audio/video information is within the secondperiod, the controller is configured to, based on at least a portion ofthe control information, allow the reproducer to reproduce theaudio/video information, wherein, in a case where the controllerconfirms that a reproduction of the audio/video information is startedbefore an end of the first period and the reproduction is continuing atthe end of the first period, the controller is configured to, based onat least a portion of the control information, allow the reproducer toreproduce the audio/video information to an end of the audio/videoinformation beyond the end of the first period and thereafter not allowthe reproducer to start an another reproduction of the audio/videoinformation even if an elapsed time from a start of an initialreproduction of the audio/video information is within the second period.38. The method according to claim 37, wherein the control informationincludes data indicative of user identification information forpermitting a specified user to reproduce the audio/video information.39. The method according to claim 37, wherein the reproduction to theend of the audio/video information beyond the end of the first period isenabled if the reproduction is not stopped.
 40. A method, comprising:receiving a request of a user by a receiver; transmitting an audio/videoinformation to an external reproducing system by a transmitter inresponse to the request of the user, wherein the audio/video informationis encrypted according to a predetermined encryption method and isrestricted from reproduction based on at least a portion of controlinformation, including data indicative of a first period for enabling areproduction of the audio/video information and disabling reproductionafter expiration of a prescribed time and a second period, that beginsat a start of an initial reproduction of the audio/video informationwithin the first period and is shorter than the first period, forenabling a reproduction of the audio/video information and disablingreproduction after expiration of a prescribed time following the startof the initial reproduction of the audio/video information; wherein atleast a portion of the control information is for controlling areproduction of the external reproducing system, in a case where anelapsed time from a start of the first period is within the first periodand an elapsed time from a start of an initial reproduction of theaudio/video information is within the second period, to allow thereproduction of the audio/video information by the external reproducingsystem, and, in a case where a reproduction of the audio/videoinformation by the external reproducing system is started before an endof the first period and the reproduction is continuing at the end of thefirst period, to allow the reproduction to an end of the audio/videoinformation beyond the end of the first period and thereafter not allowa start of an another reproduction of the audio/video information evenif an elapsed time from a start of an initial reproduction of theaudio/video information is within the second period.
 41. The methodaccording to claim 40, wherein the transmitter is configured to transmitthe audio/video information with at least a portion of the controlinformation related to the audio/video information to the externalreproducing system.
 42. The method according to claim 40, wherein atleast a portion of the control information to be transmitted by thetransmitter is embedded as a watermark in the encrypted audio/videoinformation.
 43. The method according to claim 40, wherein the controlinformation includes data indicative of user identification informationfor permitting a specified user to reproduce the audio/videoinformation.
 44. The method according to claim 40, wherein, in a casethat the audio/video information is reproduced once by the externalreproducing system and thereafter moved to another external reproducingsystem, a reproduction of the audio/video information moved to the otherexternal reproducing system is restricted based on a period which isdecremented from at least one of the first period or the second period.45. The method according to claim 40, further comprising encrypting theaudio/video information by a encryptor in advance of transmitting to theexternal reproducing system.